(a) Field of the Invention
The present invention relates to tin balls of a ball grid array seat, and particularly to a manufacturing method for fixing tin balls in one of a connector or an IC device.
(b) Description of the Prior Art
Conventionally, electric connectors, CPUs, chips, zero insertion electric connector or electric elements are welded to a circuit board. A plurality of terminals embedding holes are punched on a circuit board for embedding a plurality of terminals. Then the terminals are welded and fixed by tin material. This way is not preferred for terminals with a larger number of pins and with slender pins. Therefore, it is not adapted in the current electronic technology. To improve the defects in the prior art, the bottom of the terminals are combined with tin balls which are then welded to a circuit board.
However, the tin balls are adhered to a circuit board by various ways, for example, the welding portion of a terminal is formed with two copper clips or, as shown in FIGS. 10 and 11, the welding portion 101 of a terminal 10 is formed as a plane and welding assisting agent 102 is used in welding (referring to FIG. 12). Therefore, the manufacturer must prepare several producing lines for these tedious works so that the costs in manufacturing and repair are high. Moreover, the forms of the terminals are fixed and cannot be designed as desired.
For the manufacturing method that the plane welding portion of the a terminal 10 is combined with melted tin ball 20 using a welding assisting agent (referring to FIG. 10 and 11), the welding portion 101 of the terminal 10 has a plane structure so that the welding assisting agent can be printed upon the welding portion 101. If the welding portion has a needle shape or an embedded shape, the welding portion is not suitable for printing the welding assistant agent. Therefore, the prior art is not a preferred way and cannot be used in various terminal structures.